Fig. 1From: Micro-evolution of three Streptococcus species: selection, antigenic variation, and horizontal gene inflowDistribution of orthologous groups (OGs) by the number of strains in which they are present. a For all analyzed strains (25 S. suis, 28 S. pneumoniae, and 50 S. pyogenes). b For 25 strains of S. suis with fitting by the sum of three exponential functions and by the sum of two power functionsBack to article page